1. Field
This document relates to a stereoscopic image display comprising a 3D filter.
2. Related Art
A stereoscopic image display device displays a stereoscopic image, i.e., a three-dimensional (3D) image using a stereoscopic technique or an autostereoscopic technique. The stereoscopic technique, which uses a parallax image of left and right eyes of a user with a high stereoscopic effect, includes a glasses method and a non-glasses method, which have been put to practical use. In the glasses method, left and right parallax images each having a different polarization direction are displayed on a direct-view display or projector, and a stereoscopic image is displayed using polarization glasses or liquid crystal shutter glasses. In the non-glasses method, optical parts, such as a parallax barrier and a lenticular lens, are installed in front of a display screen to separate optical axes of left and right parallax images.
The glasses-type stereoscopic image display is divided into a stereoscopic image display using polarization glasses and a stereoscopic image display using shutter glasses. In the stereoscopic image display using polarization glasses, a polarization separation element, such as a pattern retarder, is required to be attached on the display panel. The pattern retarder renders the polarization of the left and right-eyed images displayed on the display panel to be different from each other. When watching a stereoscopic image displayed on the stereoscopic image display using polarization glasses, a viewer sees polarized light of the left-eyed image through a left-eyed filter of the polarization glasses and polarized light of the right-eyed image through a right-eyed filter of the polarization glasses, thereby perceiving a 3D effect.
The parallax barrier, the lenticular lens, and the patterned retarder are implemented as a 3D filter, which has a liquid crystal layer formed between two transparent substrates and electrodes formed on the substrates. Thus, the driving state of the 3D filter can be electrically controlled. Such a 3D filter is adhered to the display panel, and can switch between 2D image and 3D image by changing or refracting the traveling path of light incident from the display panel by using dielectric anisotropy and refractive index anisotropy of liquid crystal molecules.
The 3D filter comprises electrodes for applying an electric filed to the liquid crystal layer. When overcurrent is applied to an electrode pattern during the inspection or driving of the 3D filter, edge portions of the electrode pattern may be burnt or shorted. In this case, the 3D filter cannot be properly driven.